In a traditional automatic transmission system for a vehicle, a shifter is connected to the transmission by a mechanical linkage to change the gears or ranges of the transmission. The transmission ranges may include, but are not limited to, Park, Neutral, Reverse, and Drive. However, shift-by-wire transmission systems have been developed where the mechanical linkage is replaced by an electronic connection through which an electronic signal is sent to the transmission to effect the changing of the transmission ranges. The electronic signal may be activated via a shift lever, buttons, and the like. For example, in some shift-by-wire systems, the transmission may be placed in the Neutral, Reverse, and Drive transmission ranges via a shift lever, and in the Park transmission range via a dedicated park button. In the event that there is a fault with at least one of the electronic signals generated by the shift lever and/or the park button, or if both are activated at the same time, the shift-by-wire system may place the vehicle in a Park mode.